This application claims the priority of German patent document 103 22 828.4, filed 19 May 2003, the disclosure of which is expressly incorporated by reference herein.
The invention relates to a control system for a vehicle having a towing component with an electronically actuatable drive train, and a towed component.
German patent document DE 100 32 179 A1 discloses a control system of this type in which the vehicle is equipped with an electronically actuatable drive train having at least a steering system, a brake system and a drive assembly. Such control systems for vehicles with an electronically actuatable drive train are also referred to as drive-by-wire systems or as X by-wire systems. In such systems, the steering system, brake system and drive assembly of the vehicle can be controlled electronically without there being a continuous mechanical or hydraulic connection between corresponding operator control elements such as the steering wheel, brake pedal and accelerator pedal and the respective component of the drive train.
The control system comprises an operator control device which is fixed to the vehicle and into which a driver of the vehicle inputs a driver request by means of corresponding operator control elements such as a steering wheel, a brake pedal and an accelerator pedal. The operator control device generates a standardized movement vector from the driver request. The movement vector corresponds here, for example to a bus protocol, in particular a CAN protocol. The operator control device thus forms an input level for predefined values (driver requests) which are to be processed by the drive train.
The control system also comprises a control device which generates and outputs control signals for actuating the drive train from an input movement vector. The control signals are then transmitted to and processed by the drive train, in order to implement the driver request. The control device thus forms a coordination level which permits the standardized setpoint signals (driver request) to be implemented at the drive train.
In a “train” composed of a towing vehicle and trailer, maneuvering (particularly reversing) is comparatively difficult due to the complex kinematics between the towing vehicle and trailer, and even an experienced driver requires a comparatively large amount of time to carry it out. Such an articulated train has two steered wheel axles, one for the towing vehicle and one for the trailer, so that the kinematic coupling between the towing vehicle and trailer for reversing the train is complex.
Furthermore, an additional person is necessary to give instructions in order to reduce risks of collision between the train and obstacles. Since the person giving instructions is superfluous in terms of the actual function of the train, which is generally to transport a payload from a starting location to a destination, it is worthwhile to simplify the maneuvering of the train to such an extent that it can be carried out without a person giving instructions.
One object of the present invention is to provide a control system of the type described, which simplifies in particular the maneuvering and reversing of the train.
This and other objects and advantages are achieved by the control system according to the invention, in which the problem of reversing a train is reduced to a comparatively simple reversing problem for a single-element vehicle which has only one steered wheel axle. The reversing of a single-element vehicle with a steered front axle corresponds to the reversing of a normal passenger car and can therefore be carried out comparatively easily. In the present invention, the driver of the vehicle predefines a setpoint value for the trailer steering angle of a wheel axle which steers the trailer, using a corresponding setpoint value sensor. The setpoint value steers the trailer to the desired destination when the vehicle is reversed.
For this purpose, the invention provides a reversing device which, in an active state, determines a steering setpoint angle from the trailer setpoint steering angle (selected by the driver) and a current trailer actual steering angle for the steering system of the towing vehicle. The steering setpoint angle is calculated in such a way that, when it is implemented in a moving train, it changes the trailer steering angle to the desired setpoint value. In other words, the reversing device takes into account the complex kinematics between the towing vehicle and the trailer and generates, at the towing vehicle, a steering activation which brings about the steering activation at the trailer which is desired by the driver as the train moves. Maneuvering, and in particular reversing the train, can thus be considerably simplified.
Implementing the reversing device in the control system is comparatively simple here since only one modified movement vector has to be generated using the reversing device. This vector then brings about the desired steering movement of the trailer when the train moves.
In one advantageous embodiment, the driver of the vehicle inputs a driver request into a remote control device and which generates the movement vector from the driver request. A transceiver arrangement permits the necessary communication between the remote control device (which is remote from the vehicle), the reversing device and the control device. The communication expediently takes place by means of a drive train interface arrangement. The remote control device can have a trailer steering angle setpoint value sensor, so that it is particularly easy for the driver of the vehicle to predefine the necessary trailer setpoint steering angle by positioning himself at a suitable location in the vicinity of the trailer.
According to an advantageous embodiment of the invention, in the active state, the reversing device utilizes a towing vehicle steering angle setpoint value sensor (in particular that of the remote control device) as a trailer steering angle setpoint value sensor. In the passive state of the reversing device, the driver of the vehicle uses the towing vehicle steering angle setpoint value sensor of the cockpit and/or of the remote control device to input towing vehicle setpoint steering angles; while in the active state, the reversing device uses the towing vehicle setpoint steering angles which can be tapped at the towing vehicle steering angle setpoint value sensor present at the trailer setpoint steering angle. The invention thus makes use of a towing vehicle steering angle setpoint value sensor which is present in any case and gives it a double function. The reversing device is thus implemented without the need for additional steering angle setpoint value sensors for the trailer, and is therefore comparatively economical.
It goes without saying that the features which are mentioned above and the features which are to be explained below can be used not only in the respectively specified combination but also in other combinations or in isolation without departing from the scope of the present invention.